Fine motor development involves greater use of the hands to perform more precise tasks. By 6 -12 months children should be able to reach for small objects and pass an object from one hand to the other. From 1 -2 years they can perform more complex tasks such a building a tower of blocks, feeding themselves, and turning knobs. In terms of pencil skills, they should be able to imitate scribbles and then spontaneously scribble. By the age of 2 years they can draw a line, and by three they can draw a circle. From the age of 3.5 they can draw a cross, 4.5 – a square, 5 – a triangle, and 6 a diamond.

Among the options provided, an 8-week-old full-term infant with normal developmental milestones will smile in response to appropriate stimuli.Rationale:Smiles in response to appropriate stimuli are seen from around 6 weeks of age. A social smile, where the infant has an awareness that a smile attracts attention, is not observed until around 3 months of age.Other options:- At 6 weeks an infant is able to follow objects in the horizontal plane through 90 deg; fixing and following an object through 180 deg in the horizontal plane is a milestone achieved at 3 months, as is pushing up onto forearms. – Pushing up onto hands occurs by around 5 months.- Infants of 3 months should startle to a 60 dB sound.

3-year-old milestonesSocial and EmotionalCopies adults and friends Shows affection for friends without prompting Takes turns in games Shows concern for crying friend Understands the idea of mineť and hisť or hersť Shows a wide range of emotions Separates easily from mom and dad May get upset with major changes in routineDresses and undresses self Language/CommunicationFollows instructions with 2 or 3 steps Can name most familiar things Understands words like in,ť on,ť and underť Says first name, age, and sexNames a friend Says words like I,ť me,ť we,ť and youť and some plurals (cars, dogs, cats) Talks well enough for strangers to understand most of the time Carries on a conversation using 2 to 3 sentences Cognitive (learning, thinking, problem-solving)Can work toys with buttons, levers, and moving parts Plays make-believe with dolls, animals, and people Does puzzles with 3 or 4 pieces Understands what twoť means Copies a circle with a pencil or crayon Turns book pages one at a time Builds towers of more than 6 blocks Screws and unscrews jar lids or turns the door handle Movement/Physical DevelopmentClimbs well Runs easily Pedals a tricycle (3-wheel bike) Walks up and downstairs one foot on each step

Language/Communication milestones of 2 years old:Points to things or pictures when they are named Knows names of familiar people and body parts Says sentences with 2 to 4 words Follows simple instructions Repeats words overheard in conversation Points to things in a book

All the given development milestones are compatible with the given age.

A 2 year old child who is developing normally should be able to point to three body parts, identify familiar objects in his environment such as a crayon or a toy and follow simple instructions.At 3 years old he should be able to copy a circle, jump up and down and name three colours.

Milestones of 6 monthsSocial and EmotionalKnows familiar faces and begins to know if someone is a stranger Likes to play with others, especially parents Responds to other people’s emotions and often seems happy Likes to look at self in a mirror Language/CommunicationResponds to sounds by making sounds Strings vowels together when babbling (ah,ť eh,ť ohť) and likes taking turns with the parent while making sounds Responds to own name Makes sounds to show joy and displeasure Begins to say consonant sounds (jabbering with m,ť bť) Cognitive (learning, thinking, problem-solving)Looks around at things nearby Brings things to mouth Shows curiosity about things and tries to get things that are out of reach Begins to pass things from one hand to the other Movement/Physical DevelopmentRolls over in both directions (front to back, back to front) Begins to sit without support When standing, supports weight on legs and might bounce Rocks back and forth, sometimes crawling backwards before moving forward

By the age of three months a child should become more fascinated with their hands and fingers; they can bring their hand to their mouth, open and close their hand, and shake and grab at dangling objects and toys. Their ability to roll over will come by the time the child is 6 months, at which time they will also be able to sit with support. Soon, at 8-9 months, attempts will be made to crawl and as they approach 12 months they will be able to pull on objects to stand.

A three-year child’s typical developmental milestones include walking up and down the stairs with alternating feet, jumping in a place with two feet together, and jumping forward for about 2 feet. The child can pedal a tricycle and can throw a ball over and underhand. An average child should start walking around 12-14 months of age and should be investigated as early as 18 months if they do not begin to walk. Skipping can be done by a child of 5 years of age. A child of 6-7 years of age can ride a bike with stabilizers and can balance on one foot for 20 seconds.

In a child with an age of 12 months – pincer grasp should be well developed. It is essential to have a good grasp of important milestones. Most 12-month-old children will be mobile, by standing holding onto a support, lifting one foot and moving it sideways (‘cruising’ around the furniture). They will demonstrate a neat pincer grasp, e.g. picking up a raisin or piece of paper between the tip of the index finger and the thumb. Words (or meaningful word-like utterances) are produced, but words are not usually chosen and put together deliberately by a child until after the second birthday (typically around the age of 30 months). Word combinations used earlier than this are likely to be an echo of a learnt phrase which may be understood by the child to be one single word even though they are a combination of more than one word (e.g. daddy, home). Building a tower of three cubes and following a one-step command such as ‘take off your socks’, is expected at 18 months.

Jacob is likely to be four years old as demonstrated by his activities throughout the day. Most 4 year olds are able to run well, jump and hop, but find skipping a little more difficult. They are able to brush their teeth and dress themselves with supervision, and go to the toilet alone.

Among the provided options, we would expect a normally developing six-month-old child to have lost Moro’s reflex.Note:The Moro reflex is present from birth and persists until 4 months of age. It is abnormal for the Moro reflex to persist much beyond this stage, and if it does, cerebral palsy should be considered.A normal 6-month old baby should be able to roll over from front to back, readily follow objects with their eyes, transfer objects from hand to hand, recognise parental voices and babble and laugh.Other options:- Having a pincer grip is more typical of a 9-12-month-old.- Although at 6 months babies are often able to sit briefly or with support, sitting steadily is typically seen at 9 months.- Starting to stand with support is more typical of a 9-12-month-old.- Waving bye-bye is more typical of a 9-12-month-old.

A 3 year old should be able to match two colours, copy a circle, walk up and down the stairs, and jump up and down. By the time they are 4 they can copy a cross, draw a person with three parts, count to 10, stand on one foot.

By the age of 3 months Jasmine should startle to loud noises, recognise her parents voices and turn to them when they are speaking, and should quiet down or smile at the sound of a familiar voice when crying. She should also cry when she is uncomfortable or irritated. By the time Jasmine is 9 months old she would begin to understand and respond to the word ‘no’ as well as other easy commands. She would be able vocalise and babble with repetitive sounds, and imitate adults’ playful sounds. She would be much less likely startled by loud noises.

4-year-old milestonesSocial and EmotionalEnjoys doing new things Plays Momť and Dadť Is more and more creative with make-believe play Would rather play with other children than by himself Cooperates with other children Often can’t tell what’s real and what’s make-believe Talks about what she likes and what she is interested in Language/CommunicationKnows some basic rules of grammar, such as correctly using heť and sheť Sings a song or says a poem from memory such as the Itsy Bitsy Spiderť or the Wheels on the Busť Tells stories Can say first and last nameCognitive (learning, thinking, problem-solving)Names some colours and some numbers Understands the idea of counting Starts to understand time Remembers parts of a story Understands the idea of sameť and differentť Draws a person with 2 to 4 body parts Uses scissors Starts to copy some capital letters Plays board or card games Tells you what he thinks is going to happen next in a book Movement/Physical DevelopmentHops and stands on one foot up to 2 seconds Catches a bounced ball most of the time Pours, cuts with supervision, and mashes own food

Primitive reflexes are central nervous system responses, many of which disappear as a child matures. Retention of these reflexes may point to atypical neurology such as in cerebral palsy or stroke. However, some persist into adulthood. The stepping reflex is present from birth and normally disappears by 6 weeks, while the moro reflex is present from birth to about 4 months. The asymmetrical tonic neck reflex disappears by about 6 months. Reflexes that persist include the head righting reflex which develops at 6 months, and the parachute reflex which develops at 9 months.

From the given clinical scenario, the peroxisomal disorder in question is Refsum’s disease.It is characterised by anosmia, early-onset retinitis pigmentosa (night blindness), chronic ataxia, variable neuropathy, deafness and ichthyosis. It is an inherited disorder of fatty acid oxidation with phytanic acid accumulation in the blood and tissues. This leads to the motor and sensory neuropathy. Other options:- Loss of sensation in extremities, dysarthria and diabetes is suggestive of Friedrich’s Ataxia. It is the most common autosomal recessive cause of ataxia. Associated features include dysarthria, scoliosis, diabetes and hypertrophic cardiomyopathy. – Numbness of the limbs, seizures and developmental delay suggests mitochondrial cytopathy such as NARP (Neuropathy, Ataxia and Retinitis Pigmentosa). Learning difficulties, developmental delays and convulsions are not uncommon, as with many mitochondrial disorders. – Rapid, chaotic eye movements, behaviour change and irritability, suggest opsoclonus-myoclonus syndrome. It is thought to be a Para infectious or paraneoplastic condition (secondary to neuroblastoma) linked to an abnormal immune response. Children present unwell with altered behaviour, irritability, ataxia, random chaotic eye movements and later myoclonus. – Sweet-smelling urine, lethargy and seizures suggest Maple Syrup Urine Disease (MSUD). It is an autosomal recessive organic acidaemia. There is a distinct sweet odour to the urine of affected individuals, particularly at times of acute illness. Without treatment, MSUD can lead to seizures, brain damage, coma and death. The most common and classic form affects babies shortly after birth, but variant forms may not be evident until later childhood.

Not being able to form a sentence at the age of 18 months is quite normal. A combination of two words to form a sentence can be done by 2 years of age.

18-month-old milestonesSocial and EmotionalLikes to hand things to others as play May have temper tantrums May be afraid of strangers Shows affection to familiar people Plays simple pretend, such as feeding a doll May cling to caregivers in new situations Points to show others something interesting Explores alone but with parent close by Language/CommunicationSays several single words Says and shakes head noť Points to show someone what he wants Cognitive (learning, thinking, problem-solving)Knows what ordinary things are for; for example, telephone, brush, spoon Points to get the attention of others Shows interest in a doll or stuffed animal by pretending to feed Points to one body part Scribbles on his own Can follow 1-step verbal commands without any gestures; for example, sits when you say sit downť Movement/Physical DevelopmentWalks alone May walk up steps and run Pulls toys while walking Can help undress herself Drinks from a cup Eats with a spoon

6 month old babies that go through normal developmental milestones, should enjoy playing with others and especially their parents.The other milestones are expected of a 9-month-old.

Among the given options a 2-year-old child with normal developmental milestones will be able to pull and push large wheeled toys and squat to play with toys on the floor.Other options:- Bouncing and catching a ball is learnt by the age of 5.- The ability to pedal a tricycle should be attained by 3 years of age, not 2.- A child can walk on tip-toe by 2.5 and run on tip-toe by (option D) 3 years of age, not 2.- The ability to momentarily maintain balance using one leg (option E) should be attained by 3 years.

At the age of three years a child is to be able to dress and undress himself with supervision, eat with a spoon and fork, build a tower with 9 cubes, give their full name and copy a circle. The child will not be able to make good cuts with scissions until he is about 5 years old.

Among the options provided, a 1-year-old child will be able to understand object permanence e.g. understands that objects continue to exist even when they can’t be seen, e.g. looking for a fallen toy.At the age of 1 year, children should have developed an accurate pincer grip and be able to see and co-ordinate and manipulate fairly small objects such as a raisin.Gross motor development varies, but the average 1-year-old should be able to stand and cruise around furniture or walk with their hands held but not necessarily walk unaided.Drinking from a cup will become established at around 15 months and scribbling at 18 months.

Toe walking refers to a pattern of walking in which the infants walk on the balls of their feet, without putting the heel of the feet on the ground. It is considered normal under the age of 2 years, but if it continues beyond that, it can signify some underlying pathology. The diseases that can be associated with toe walking include unilateral hip dislocation, Spinal tumours, Duchenne muscular dystrophy, prematurity, and cerebral palsy. Waardenburg’s syndrome is an autosomal dominant disorder, causing sensorineural deafness, and heterochromatic irises. Toe walking is not a feature.

Based on the presentation, the developmental age of the child is 8 months.The primitive reflexes are indicators of functional integrity and maturity. The majority of reflexes do not persist beyond 6 months of age. There are 13 reflexes of importance, including:- Moro reflex- Startle reflex- Rooting reflex- Sucking reflex- Grasp reflex- Voluntary palmar grasp reflex- Voluntary reach reflex- Stepping reflex- Asymmetrical tonic neck reflex (ATNR)- Parachute reflex- Plantar reflex- Tendon reflex- ClonusIt is interesting to note that gastrocolic reflex is not a primitive reflex.Ninety-five per cent of reflexes will have disappeared by the ages shown below:- 6 weeks: Stepping- 3-4 months: Palmar grasp and Moro- 6 months: Sucking, rooting, and asymmetrical tonic neck reflex (ATNR)

Developmental milestones at the age of 2 months are as follows:Social and Emotional:- Begins to smile at people – Can briefly calm herself (may bring hands to mouth and suck on hand)- Tries to look at the parents Language/Communication:- Coos, makes gurgling sounds – Turns head toward sounds Cognitive (learning, thinking, problem-solving):- Pays attention to faces – Begins to follow things with eyes and recognize people at a distance – Begins to act bored (cries, fussy) if an activity doesn’t changeMovement/Physical Development:- Can hold head up and begins to push up when lying on tummy – Makes smoother movements with arms and legs

At 7 months, children are expected to sit briefly leaning forward on their hands, reach and grasp objects, transfer objects from hand to hand, and babble. Children are usually expected to wave goodbye or grasp objects with their fingers or thumb at around 10 months and older.

Among the provided options, we would expect a normally developing 18-month-old child to be able to carry toys while walking.At 18 months, a normally developing child will show the following gross motor abilities:- walks with the feet slightly apart- runs carefully with the head held high- pushes and pulls objects around the floor- walks upstairs if the hand is held- kneels on a flat surface without support- carry toys while walking.Other options:- Intentionally kicking a ball is a skill typically acquired by 2.5 years, not 18 months.- Jumping with two feet together from a small step is usually acquired by 2.5 years, not 18 months.- Propelling a tricycle forwards by pushing with the feet on the floor is a milestone generally acquired by 2 years, not 18 months.- Throwing a small ball overhand without falling is a milestone for children aged 2 years, not 18 months.

3-year-old milestones:Social and Emotional:- Copies adults and friends – Shows affection for friends without prompting – Takes turns in games – Shows concern for crying friend – Understands the idea of mineť and hisť or hersť – Shows a wide range of emotions – Separates easily from mom and dad – May get upset with major changes in routine- Dresses and undresses self Language/Communication- Follows instructions with 2 or 3 steps – Can name most familiar things – Understands words like in,ť on,ť and underť – Says first name, age, and sex- Names a friend – Says words like I,ť me,ť we,ť and youť and some plurals (cars, dogs, cats) – Talks well enough for strangers to understand most of the time – Carries on a conversation using 2 to 3 sentencesCognitive (learning, thinking, problem-solving)- Can work toys with buttons, levers, and moving parts – Plays make-believe with dolls, animals, and people – Does puzzles with 3 or 4 pieces – Understands what twoť means – Copies a circle with a pencil or crayon – Turns book pages one at a time – Builds towers of more than 6 blocks – Screws and unscrews jar lids or turns the door handleMovement/Physical Development- Climbs well – Runs easily – Pedals a tricycle (3-wheel bike) – Walks up and downstairs, one foot on each stepDoing up buttons is a skill more usually seen in 5-year-olds.

Milestones of 3 years old:Social and Emotional:Copies adults and friends Shows affection for friends without prompting Takes turns in games Shows concern for crying friend Understands the idea of mineť and hisť or hersť Shows a wide range of emotions Separates easily from mom and dad May get upset with major changes in routineDresses and undresses self Language/Communication:Follows instructions with 2 or 3 steps Can name most familiar things Understands words like in,ť on,ť and underť Says first name, age, and sexNames a friend Says words like I,ť me,ť we,ť and youť and some plurals (cars, dogs, cats) Talks well enough for strangers to understand most of the time Carries on a conversation using 2 to 3 sentences Cognitive (learning, thinking, problem-solving):Can work toys with buttons, levers, and moving parts Plays make-believe with dolls, animals, and people Does puzzles with 3 or 4 pieces Understands what twoť means Copies a circle with pencil or crayon Turns book pages one at a time Builds towers of more than 6 blocks Screws and unscrews jar lids or turns door handle Movement/Physical Development:Climbs well Runs easily Pedals a tricycle (3-wheel bike) Walks up and down stairs, one foot on each step