Tay Sachs Disease

Tay Sachs disease is a type of degenerating neurological disease caused by a deficiency of the enzyme protein hexosaminidase A. Because the enzyme is deficient, a lipid molecule called GM2 ganglioside builds up inside the lysosomes of cells. It's for this reason that doctors categorize it as a type of lysosomal storage disease.

The disease occurs when parents that are BOTH carriers of the genetic mutation have a baby. The most common carriers are Ashkenazi Jews, French Canadians and Louisiana Cajuns (1 in every 27), though carrier frequencies are also high in Irish Americans (1 in 50) and the general population (1 in 250). 

The disease typically occurs acutely in infancy, but there are three documented presentations: acute, subacute and late onset. 

The classic presentation, the acute (infantile) form, involves progressive motor weakness with loss of milestones and myoclonic jerking beginning at 3 months of age. 98% of patients develop seizures, and death typically occurs within the first few years of life. The severity is due a complete absence of the hexosaminidase A enzyme.

The subacute (juvenile) form will present as late as 9 years old, and is characterized by seizures, choreiform movements, speech problems and incontinence.  These children will typically develop dementia and won't live past the teenage years. 

Late onset Tay Sachs (LOTS, adult) cases have been reported in older patients, and usually involve subtle disturbances in speech, mood and psychological state. 

Pediatricians should suspect Tay Sachs Disease in any Jewish patient or patient of Jewish descent with delayed milestones and myoclonic jerks before the age of 1. Close inspection of the eye will typically reveal a cherry-red colored spot on the macula of the retina, which is only present in a few childhood diseases (Krabbe, Canavan, Alexander, and Gaucher diseases). A blood test will officially confirm the diagnosis. 

The differential diagnosis of neurologic progression in pediatric patients involves neurodegenerative disorders (spinal muscular atrophy/SMA, amyotrophic lateral sclerosis/ALS, Friedreich ataxia/FA and leukodystrophy)

Management of the disease involves maintaining nutrition, respiratory function and motor function while minimizing infectious diseases and seizures. Later forms benefit from both speech and physical therapies. All patients and their families should be referred to a certified genetic counselor for counseling. 

The prognosis for Tay Sachs disease is very poor. One retrospective study followed 97 infants diagnosed with Tay Sachs disease and noted that death occurs before the age of 5 in nearly all patients. Milestones such as head control, transferring objects from hand to hand and sitting without suport were acheived by the babies in over half the cases, but all lost their abilities by 1 year of age. The median lifespan of the infants was only 47 months.

Reference

Tay Sachs Disease. Dynamed Database. Updated May 12 2014. Accessed July 10, 2014. 

Your Child's Development: Pediatric Milestones

"Is my child developing normally?" 

This question is almost guaranteed during nearly all well child encounters in the pediatric office setting. Parents, rightfully so, are commonly concerned about their child's development and need a small amount of  reassurance from their professional caregiver. What are the guidelines that all pediatricians follow? 

The pediatrician references a set list of known guidelines when evaluating the development of a child. He or she often does this in three ways: using an Ages and Stages Questionnaire (sensitivity 75%, specificity 81%) filled out by the parent, asking the parent specific questions about the child and physically examining or interviewing the child. 

Below is the list of developmental milestones. It's important to remember two things:

1) The milestones are simply a guide: physicians use it to help determine if a child has fallen below normal when compared to other age-matched children. It is the job of the pediatrician to recognize a child that has fallen behind in one area and to offer support or resources to help him or her catch up (i.e, the Early Steps program).

2) All children develop differently. One child may meet all milestones on time while another may be persistently behind in one area. It's important to always be patient with (and supportive of) your child.

Pediatric milestones by age:

1 month

Vision: regards face, fixes transiently

Social: smiles spontaneously

6 weeks

Vision: follows to midline

Language: vocalizes (other than crying)

2 months

Hearing: alert to sound- localize by turning head and eyes

Social: cuddle when held, smiles responsively

10 weeks

Gross motor skills: lifts head prone 45-90 degrees

3 months

Language: coos (ooh, ah), laughs

Gross motor skills: head control when pulled to sitting position 

Fine motor skills: hands together

4 months

Vision: follows 180 degrees (visual tracking)

Language: squeals, makes raspberry sound, babbles d,t,z then b,m,p

Gross motor skills: may sit with support, raise head when lying prone

Fine motor skills: grasps rattle

5 months

Gross motor skills: rolls over (prone to supine)

6 months

Gross motor skills: pulls to sit without head lag, reach for toy, rolls both ways, sits with support and alone

Social: stretches arms to be picked up, shows likes

Warning sign: significant head lag, persistent fisting, persistent squint, persistent asymmetric tonic neck reflex, inability to roll over

8 months

Hearing: turns to voice

Gross motor skills: sits without support

Fine motor skills: transfers objects hand to hand, feeds self cracker

9 months

Hearing: turns directly to sound

Gross motor skills: crawls

Social: plays games, finger feeds, holds own bottle, object permanence

10 months

Gross motor skills: pulls to stand

Language: mama, dada, nonspecific, imitate speech sounds, repetitive consonants

1 year

Language: mama, dada specific one word other than mama and dada

Gross motor skills: pivots while sitting

Fine motor skills: bangs objects with hands, thumb/finger grasp, grasps by radial raking, "pincers" grasp, drops and throws toys

Social: indicates wants other than crying, comes when called

Warning sign: failure to sit without support, persistent squint

13 months

Gross motor skills: stands momentarily, cruises (stands and moves between large objects in room by hanging on)

14 months

Gross motor skills: walks well 

15 months

Language: immature jargonizing, understands "no", one-step commands, can point to body parts

Gross motor skills: climbs

18 months

Gross motor skills: kicks or throws ball

Fine motor skills: turns pages, feeds self with spoon

Social: follow simple commands, cuddles toys, enjoy imitative play, copies household tasks, plays some with others, symbolic play (thought)

Warning sign: inability to stand, no pincer grasp, no spontaneous vocalizations, abnormal hand posture

20 months

Language: 3 words other than mama/dada

2 years

Language: 50 words in vocabulary, "NO", can follow 2-part commands, points to named part of body, combines 2 words

Gross motor skills: run, walks up and down stairs with help, climb stairs alternating steps

Fine motor skills: spills little, uses cup, washes/dries hands, may help with dressing, eats by self, scribble spontaneously builds 6-cube tower, uses spoon, removes garment

Social: asks to go to toilet, plays with others (imitation), solitary parallel play (play side-by-side)

Warning sign: absence of recognizable words, lack of walking, tremor or ataxia

3 years

Language: gives first and last name, age, address, name parts of body, speech understandable to family, 3-4 word sentence, 250 word vocabulary, uses plurals, prepositions, pronouns

Gross motor skills: jumps in place, stand on 1 foot, kick ball, rides tricycle

Social: mostly toilet trained, participates in family life, plays interactive games (for example, tag)

Warning sign: speech not understood 75% of time

4 years

Gross motor skills: can heel walk, hops on 2 feet, climb ladder, tiptoe, hop, jump, balances on 1 foot for 5 seconds

Fine motor skills: dresses without supervision, copies, buttons clothes, uses pencil, glue, scissors, copies line and circle

Social: brush teeth, wash hands, toilet, separates easily from mother, enjoys jokes with parents, games with rules

5 years

Vision: recognizes 3 of 4 colors 

Language: counts 10 objects, names 4 colors; can define spoon and cat, can narrate story

Gross motor skills: skips

Fine motor skills: draws 6-part man (head, body, arms, legs), dresses/undresses without supervision, copy triangle, cut and paste

Social: understand good/bad, right/wrong

6 years 

Language: copies sound, composition of door/shoe/spoon

Gross motor skills: hop on 1 foot, walks backward heel-toe

• If you have any questions regarding your child's development, it's important to ask your pediatrician

• Research suggests that faster attainment of developmental milestones in first year of life associated with better educational outcomes at ages 16 and 31 years

• Studies have shown that bed-wetting at age 53 months is associated with a delay in developmental milestones 

• Speech should be intelligible by 3 years of age. If it isn't, the pediatrician will order a hearing evaluation

Reference

Developmental Milestones. Dynamed Database. Updated March 27, 2014. Accessed July 7, 2014.

Childhood Eczema

Eczema (atopic dermatitis) is a chronic condition caused by inflammation of the skin. It's a component of the "atopic march" which includes asthma, hay fever, and food allergy. Though the exact cause is unknown, the risk of developing eczema is higher in children with dry skin (xerosis) and those with immune dysfunction. 

Additionally, possible triggers reported include:

• irritants (wool, soaps and chemicals)
• contact allergens (latex, metals, perfumes)
• food allergens (cow's milk, eggs nuts, soy, wheat and shellfish)
• house allergens (tobacco smoke, hard water, dust mites, animal dander)
• other irritants (extreme changes in humidity, pollens, molds)

Eczema is most common in children younger than 5 years old. Studies show that 66% of patients first experienced eczema before 7 years of age. The amount of children affected by eczema varies by country and, in the United States, from state to state. Numbers reported are from 1 to as high as 22% of children younger than 18. Studies also show that preterm infants (<37 weeks gestation at birth) have a higher risk of developing the condition. 

Possible risk factors include atopy (positive reaction to at least one skin prick allergen), not breast feeding, immunosuppressants and stress.

Children with eczema are at an increased risk of skin infections caused by staph, strep, herpes simplex 1 and various fungi. Chronic itching may lead to scarring and sleep disturbances. 

The pediatrician will make the diagnosis based on physical examination. It's important to rule out conditions such as parasitic infections (scabies), fungal infections (tinea), metabolic conditions (zinc deficiency), immunological deficiencies (Wiskott-Aldrich Syndrome, dermatitis herpetiformis, lupus, HIV dermatitis), systemic disease (primary biliary cirrhosis, polycythemia vera and renal failure) and other skin conditions (contact dermatitis, ichthyosis, psoriasis and seborrheic dermatitis).

Most cases of childhood eczema improve with age, and up to 70% of cases clear by teenage years. 

The secret to managing eczema lies in both controlling the dryness of the skin and minimizing any inflammation. This includes:

• Use moisturizing soap (Dove brand preferable) at very END of bath to avoid irritation
• Moisturizing cream (such as Vaseline or Eucerin) applied immediately after bath (while still damp) to affected areas 
• An anti-inflammatory (steroid cream such as triamcinolone) may be prescribed. Use twice a day.
• Avoiding irritants or triggers

Reference

Atopic dermatitis. Dynamed database. Updated January 21 2014. Accessed July 2, 2014.

Asthma in children

Asthma is a condition of the small airways of our lungs in which hypersensitive cells are aggravated by environmental substances, leading to inflammation, swelling and poor air flow. It is estimated that 70% of cases are caused by allergic substances such as dust, pollen and pet dander. Other causes include viral illnesses, exercise and cough.

It’s estimated that in the United States, 1 in 10 children younger than 18 years suffer from asthma. Many children with asthma have experienced what is known in dermatology as the “atopic march”, which is essentially a trifecta of asthma, atopic dermatitis (eczema), food allergy and allergic rhinitis (hay fever). Additionally, having asthma makes airways of children vulnerable, putting them at increased risk for diseases like pneumonia, influenza and obstructive sleep apnea.

Signs of asthma in children younger than 2 years old include noisy breathing, grunting and cough while the classic signs in children with are wheezing, chest tightness, cough and difficulty breathing.

Pediatricians will attempt to get specific information regarding the asthma in order to both determine the level of severity and prescribe the most appropriate course of treatment. Questions asked include daytime or nighttime cough, possible triggers (such as viral illness, changing seasons, exercise, etc) and previous episodes. This can reveal special cases such as cough-variant asthma and exercise-induced asthma. Additionally, the pediatrician will want to rule out other conditions such as viral bronchiolitis, cystic fibrosis (CF), bronchopulmonary dysplasia (scarring of the lungs in premature babies) and aspiration of a foreign body. Tests ordered may include spirometry in children >5 years old (blowing into a tube to test lung strength/capacity) and/or a sweat chloride test in children younger than 3 (to rule out CF).

The treatment for asthma depends on the severity. All asthma patients, regardless of severity, are placed on a short-acting beta agonist (SABA, an inhaler) on an as needed (prn) basis. The child’s response to the treatment will be reassessed at follow up in 2-6 weeks.

There are 4 levels of asthma, organized by their level of severity:

Intermittent (episodes < 3 d/week, no nighttime awakenings)

Mild persistent (episodes 3+ d/week)

Moderate Persistent (daily episodes)

Severe Persistent (episodes throughout the day with weekly nighttime awakenings)

The treatments for each are as follows:

Intermittent: SABA prn

Mild persistent: SABA + low-dose Inhaled corticosteroids (ICS)

Moderate Persistent: SABA + medium-dose ICS

Severe Persistent: SABA + high-dose ICS + long acting beta agonist (LABA)

An oral corticosteroid, such as prednisone, may be added in very severe cases where the inhaled medication isn’t working well. The reason for this is that if the airways are severely blocked, the inhaled medication will not be able to reach the tissues to be absorbed.

If a child experiencing an asthma exacerbation is not responding to his or her treatment, experiences a late night attack or has had a severe episode in the past, it’s important to bring them to the emergency room for monitoring. They may require endotracheal intubation, IV antibiotics and/or an IV theophylline drip.

The goals of the parent should include both prevention and preparedness:

• Be sure to limit your child’s exposure to cigarette smoke, pollution, aerosol chemicals and any known triggers

• Some studies have shown that breastfeeding reduces the risk of developing asthma, and others suggest that swimming helps improve lung function and reduce the severity of exacerbations

Reference

Asthma in Children. Dynamed Database. Updated May 7, 2014. Accessed July 1, 2014.